SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc9fd53daf8b218b9f0e20279de69537857da638e75437411e12357a87ef5878' 
  AND token = 'NfCCsVSyCJeUl/kLsSBlvJUk7EdBp1SLjKM3zzqvL64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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