SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '999295f7bee956b6df809d22ba6e7ec25937c27d09ded79835d631a735b856d9' 
  AND token = 'I0XnUChT8WnYtcYK9HshPoH9wRCizWI2fLVYoy0W5cg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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