SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19162a10b516fada2eff2feaa148a950ae1c228d50385d117f5ed153cadbdd98' 
  AND token = 'mf2CpjZuM4KHS77OFkRo71kANEh3dJR49QWAUBOoVGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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