SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca29a1898fffca320baf8522a1b6e4a13651e0eaf7316718336b673fa47a748c' 
  AND token = 'JvKnFxgBhuIcVCRvKGqx7+3O3Q3BUW6GUDYLxchP8MY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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