SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e110e54895dace13412d93a2fc34bea2353d031e58a501833615a469e7482f35' 
  AND token = 'r0ts33/tT0jKCW++KXAAy7knslIjrYU/U9HyoGuH4tU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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