SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84bdf5a80a16efe006b9a83e4477b48e504f10d64d5bdaccb4a1212bbbcc24ad' 
  AND token = 'p3orjDliSW1bzsB0/HdEpGtNs+8L0eJZSignzGQox4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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