SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96c3ed2d41745ac01856b93f0a86145c4dcc7c1838c145b074d2f5111adeea47' 
  AND token = '2qH/+4YHbtj1CPmJV50qghe2ROpX9/xf9cFbJMSGkwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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