SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f79c21d42485684d44abd92dec01e28f2ca96317ed02e034590edcb9bbb70a97' 
  AND token = 'h/7bgZDb8v+uSUV0XCbIrs/fpSFqBZFRLE6HV3y8AWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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