SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee97fee06a3d350e3c68010a8f232002e136ccec78d1ffe9569587438bc515b6' 
  AND token = '9roFxPSeJO1veGab6PA+qcR0nkm96YhA5OA6wm941WQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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