SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7235af283eb9b93334b32099d5d8b10cfe3aa1f215515517b2b76091b540b914' 
  AND token = '8JEX82qKLqMdpEzi7b/kapddKyeERlOFo9AwKU1JA2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}