SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fab5cf6662abe8494e6956b180c9e9f941f30a088b46ba83bca511cfb6c6901d' 
  AND token = 'eGQRalN/sZqB5PPJKw3RZ9yepKBjS4gphTpb5t8iyq8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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