SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '42532a9181a5a2bca4371408297bbda62237b64099a8e7a7beeece067e0cca6f' 
  AND token = 'b2OFTLOxVkKRW2u9GWB+xuLteeT38lpeV/0OEimVc2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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