SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32a592c76dae02e9d963a6aeb5709c49345baabd449e5ede0bdd9765cadde1a7' 
  AND token = 'FkBiKF2RnLwChuBXmk0Ts7NOSmkPI9bD8PkXS5wYNhs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}