SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '151ea4d58d416ead8c58e54c4922b1ce6fd6ff02a81e3fa5885074db323e48ac' 
  AND token = 'lcC7tNgepbjgZ0UYQqpCx7j5M4hBhdmI+gmJMGR3/bI=' 
  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"
    }
  }
}