SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '750248f1d172b9cab67f14f5a98cfff325ac797f1b2a55641c8ee35d90abee22' 
  AND token = 'ggxskrHP9QLLdmzQWEBYMj8YWysOoRQ4cPSJJ4QXn7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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