SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95d541982a997a6540ee4092f223aebbeb24bb163c91988c52b3e64ea0d0c1e7' 
  AND token = 'BVhE7Dt+xU0EYIgPgrwkhHX27/KDEn4xc+qY8/vgdjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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