SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7ad7168a8998ef3ebcbbbcafdb99d8a7e414a788a55f95d6e8f64f7a34eec21' 
  AND token = 'hIfmS5Iuncjht2J4udS0TyFMG3H2gkrMWPgoL2Dr/jI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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