SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da27ceb26a53123fd0d93421fb6e498647e35ae1668e2b7fcad2501b6f485229' 
  AND token = 'j++RjL1JqBmbZrfwmVRtTc3ECCV32wmpcQ97UYY/hVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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