SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5657ebd8bbe24f3841d0d1fa2200657f5018e896b536afd74768df0fb94a79b7' 
  AND token = '28HRNu589bvNCHJaLk3DVOnuZ39OOqSU4giSA+VOGJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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