SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c475f40597697dc63057861819c6b0ba509aa3466344718c5dfa29032a377249' 
  AND token = 'tO4OQ6a0stcutSeo/qjJiO3pyV9LDW2MUYVwHn8kX30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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