SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53eee06ad107c390d91c5e5dfea5c26829e7690588363cc77f3745bf524fe491' 
  AND token = 'rngbAqNGWSvawa/3VJmufXO6tNW+d5We3WJN40N9RbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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