SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f0e4c46b900bf36ea969902b00bf6654ef7a81c9215e6fdd015fb0a79c6c4af' 
  AND token = 'WAzY58IqnlP1P0aowhmjOfKQuIptmUkqU+N9yuzmIOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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