SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b0716ac7910596d7409934793ef4ce9bece30325b1dad7db5ce32582d7c4826' 
  AND token = 'vSO1cVo5gGxDzyNVElfoqCs+dzB7ajqSXcXBJPsgLt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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