SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a3f30d405ea8f564a987fbfb4ad05774c34845b656563d9b468117055e3b345' 
  AND token = 'hs4wQKflRFhaL2uuJPU4FtvXIHzx6tHjRklzCimgXyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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