SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd105d06fb13f2c9409ba584107ba6f1cc19ffb27343df797c057b082764b93ad' 
  AND token = 'NU8NhnJk7qb/AG/zwxXLMb9FsRopDMqfCvSxuw1Qi+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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