SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a598505036fb05753b26913691783e2975b5c5b6744ebd81b44ab9e458a6c0da' 
  AND token = 'eCQyotOleiEbAfp4be77HJGRnI/icfLWSWGlNdC3PTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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