SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89b8366580f98776dd53c1e720b22c26dd9714cdecc7190128347163ed2a2636' 
  AND token = '/3zbHltApjGVKq22qAIpVaRbE8fSZlrk6YJLABEM3UE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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