SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c6d7fdd839bb86d5dbd2d9a21cc6bba13f7dd26f558d3348caa24030f68b6da' 
  AND token = '5fq3lTzLc3i0pnhyrqruaA4o6UJScS8jiRNBTOo4AJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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