SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0575b67d4e74b758e8ec76d8ceaa172d3f073d096f1306bd404a4b5c963a9434' 
  AND token = 'kS6cb1MLRE8lNfgg4Vr0gQCagwgZPQ8ap5gLUBQocCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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