SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1c4753b851d016d1172e4fb9d543b2da93ac19677443f9c38b4e4926a6df68b' 
  AND token = 'uhq5QD9wUyedCyMbTiaNOdsKKU3+Og4yrHdVfCE9pMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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