SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '572d258aafe41ce5c4a4bbbf14a4cd50a8837ff18d98eea64f19b6853707941b' 
  AND token = 'blkR6InLzHi64WrveHLI2lrQw+eSbZTGgn/Q8kJuUtY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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