SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb71edf51d0995ec6fc5e2f97db408d80df76304fe7890341ade6e4387f9b52e' 
  AND token = 'oWnJIEFma7SNee1dSZPqbqkK1I1fgt6Y9ThI3IcsWLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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