SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3cf9e944d63d1d1d1f5c1387c80aadb0cac80a6ccbce56c982fe970c798d3ff' 
  AND token = 'HGQUf2tfjvZxFjcMVKtnS5cBpuXOFo072evTpRly2bM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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