SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a624743049ea330d1d8e3906e59615b65c07373e34d96ef9c9be653f227b514a' 
  AND token = 'Nl+/Xa3HOjFhh7IAJKHuSEZh+0QpU1BJg/mGNWdp/E8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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