SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a72720ede74a31a17267dfb83c7a832a6598de95d43334af7bd7f2e42167bd6e' 
  AND token = 'mVEH57QJ94u6HIktKIvGGqBcfiuQYm0WSoxTawQkTWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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