SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fd29787e70534dfd6244d84ca07a20739f9837a987ffbe61ac9045377a1928e9' 
  AND token = 'WO2JbbP8RsYwHgezRXJuNF2SRW5uPHPxyiLVqXUgspE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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