SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b17079a50cac151397c9559694cf2dbf1b1298bab6c552298d2ef7cfef0bc2b' 
  AND token = 'DNoWp4ZsZ1O2yNwGHg9ZKt2OmQ3E2N4mzqUpdhBvj/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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