SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e583b60ebebda852611b37a91ee9821d21d1ceaaf6d4bcb4988a97d0b090cf65' 
  AND token = 'UWUtmcCOG7I+Kb5IjeLjiQvIdshSpXW3Uis5cieQz5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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