SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c863b940f63c23d5182f6faf2cfd9b03e01de9d97980b41fc6e620cab1f90ebb' 
  AND token = '+2s3KZ2x50VjYbE/gZEghPVqOBL49qClN5QhDOKo5KU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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