SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a46be97f86d91424a59fdf8277c6db9ff4bc584addaf9532547f62b402a0fb0b' 
  AND token = 'iMVLOTjJZ1TN5dm8yCmLQSUuoTgrXNtJiqOhkRpZwsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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