SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1989d4d779c55af2a041ddb95e99585cb24a2d352f840a21cabaa5ea48db9a6' 
  AND token = 'SYI4bkZINbP2Kn/DGrnwnhjeqhQgQMzziXJvbftuJYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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