SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af309630c9e2e8b4530cf527230a0d50f4e40f32acb5b15834f2693094ca8901' 
  AND token = 'NWMbz6IGtL36fbCumqGyder5iBBSLaCqlzViwadgnLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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