SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e14ad90a092bd39f1f68bc552bebcc5f3cf756d9fe703bebef2c03cce98ba495' 
  AND token = 'FMfdGAXczAOjdq0AffB2IEUgQZEQ2ETJhVSVAsWhMs4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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