SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d75fc0fef64b7d1af15171a948f6d90fa489abec6433bf1321980179adbb485' 
  AND token = 'isqcf5HlKmxu+xzkyV7zkilVqohMHRYLv5A7RkvH/Ag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}