SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32de66ee80f90bb054b8e101f77ddc49f3ea959405da48c955650a5fd864e98d' 
  AND token = 'inmFXRAXGumptRsiD5DKOJD+eqI5PtLLgixBEukiNlw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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