SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93ba67a0d11d9ec1b2cbd46938ee7b6795753bf9bf6acca2a18a63214fa024cd' 
  AND token = '+ybVqefvk3alEwA9oaPhR8Voo07h0tvbU8stnfVBQsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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