SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee64f54649409845d83295f09bad1f289783a46b5578031a416c500473367ec5' 
  AND token = 'cfPUu7dl6Xb6owZqOjoGrM6+xkyt05ji0OvaJwH5yn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}