SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4f7c2a26c0aeab0866a453d121252dccebd582ad019d361a31ddbacc6169d5b' 
  AND token = 'EC2qWAraNRLdtxy3eVOHNJsLGicv7idkv+mow/vPpsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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