SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bf42c973c8e05239fba1951736d6ad5826a80f1edbc869b3e9ca92fd7a6c8827' 
  AND token = 'ZnACK5v1N/4S4oA5cN5vRAIJ6RVhxaLVkDMXCsvN+h0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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