SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b901661a7b4611938a0985150c2f3c9462ada4d5c757076a99e032edb693067f' 
  AND token = 'fyBn0WBWan9r0o3c2ZyaETg6qOc0o2we9HCk5O4tas8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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