SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee9967b6cda4fdbb79019dd8cbee235838c00efdf6e5a3fd590f1f0969ded236' 
  AND token = '7hLoHcouPJMcfxWg9cGsb5c/DEAKR5vQVcW3Y7sDGyI=' 
  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"
    }
  }
}