SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc2c6ab37a680452fa3cdc46c5dc956b0c87622243888fc4e2d05e237cb17c24' 
  AND token = 'NkN1rjNi0IhNEHLdDdhmeKkLIKBMMNSXB6aINXYYWOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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