SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62d8255449bc6d7335c352bdf3822ecf7d4dab42d73bc763921abd4803ab8b0c' 
  AND token = '4ycF+sL5zOtTzqNsebFdPVmkv1Ysy9USWgObuOkCo+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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