SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7fd0bd416bc8495aa29931f34bb5d4de09eaff3d8a52ef0c33743d77d85a121' 
  AND token = '2TKlnmirEOg/XpncNb8rOqaVDfseztwJLzPgT0ao8OU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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