SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4e84ff39799de2c3e6adb1700d72946beb8e31e957cf3853e8b2bcb804171c2' 
  AND token = 's/qmKtojbGVV5PZZ0l0FglX71cx5v6NGgG+PE4VawDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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