SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '849fda04123dafd608ee55db3f0272e08b5a47ad146f936d664cbdadb0a3113a' 
  AND token = 'xCMk3qxfuZHkIWW2UdhQGHraUM4k3DYeCbcu7tpBNXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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