SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a702643369359fcd85a5dda66b94f1b6b182c12dc84f471fccb6d882f4247dcb' 
  AND token = '14boIdRq8aIPXaiGCufZ7q5W9n/8hV0TTzkuSA8Iajw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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