SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5d1f97b03bbabf12e049943865f02db25aa2fdd46cdc75baae4cb3c73715785' 
  AND token = 'qrSTL/Wyj4+aITyKXp4aS03R8MPpPfkQaEIt2XqIh/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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