SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4671f222beabd4e079377090d573b55eee3820aca263310ccdfe027830461ed7' 
  AND token = 'EZreujBGrSAMiA/Bn/ld3iaeISSwbMRdk5+KEYFyU/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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