SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a3a9156f94037b96fd97a24401d4261a2cb2ceb8453814907ed0b15a9600b9b' 
  AND token = 'p16vD7o+/W3t9qeQnU4J0tF7b1fOJVOZIAmK767MhJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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