SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '211b650eda8f426124ffee91da589a7f31c809127d82bbddcfa079dab176bf3f' 
  AND token = 'qKI7RFXKMTeJs+EHhyi49dOgE3zGwK8IlHpsgL4hw2Y=' 
  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"
    }
  }
}