SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bf2ab3c90c63afae18bb974b68c88a56708b47a0e5ac210b043afaa656abc18c' 
  AND token = 'i/O73fQfCAfDiLrQWsCmVKyT2Ic2YjFa/3QOamJLnKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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