SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fd728cc45b0e66dad6848a26f2572379d8cc5a61e5da6e94f96d8bb2f5ad3c2' 
  AND token = 'MqBcyJskVkp/5vHifi7wKDILTCmFhhHbGSYYoWfW53E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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