SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '108e06b6bb820455406730b563fcbc037ab076575ce9ede5c5bae8337ce05f00' 
  AND token = 'WsCktlFmPzNb2Ty934pjyNLQWOyHfIIbI0c/g7XWK6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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