SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '792b1f15eb0b014f12d134ebd0c50c501929a1d26b0041c91990c0f43e92dc06' 
  AND token = 'D9PHm98SmQmAcHY5yq4ce88HYVaQC2jdfMqtQJkWvvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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