SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fdb47747ec51b18e9bef1d7e76a4d2ea4c93661d5c5c5bd867dfa7df74f27d7f' 
  AND token = 'v195ElZndpPzZ/QXIBJhZxQOgzHWrLbYWrT46MlEOyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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