SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c9447c66d6595fcb16e328d4a1b905ea504659a85722a6b5334d04fcde33bc3' 
  AND token = 'HpFpQVCJcSaqFKuYWoTjYXIAh5Z5laizCsr3S1+4+94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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